Closer scrutiny of our MRs from TSA is something I've been expecting for a while now -- I think it's good to see they're doing something productive like scrutinizing things they don't understand, rather than just occupying space and perusing the Economist.
Almost every flyer who frequents this board has probably identified weaknesses in airline and airport security by now. I think we can assume that someone with bad intentions could do the same. Since such a person may well operate under time and budget constraints, a "surveillance run" that mirrors our "mileage runs" might be the sort of behavior we could expect.
Now, if the TSA was smart, they would assign some truly-undercover FAM's to undertake mileage runs and observe the sort-of "undercover" FAM's and the other airport security weaknesses, we'd all be better off.